Postfledging parental care and unexpected foraging behaviour of juvenile Sooty Terns Onychoprion fuscata in the southern Mozambique Channel

The Berlese funnel method, and its variations, is commonly used for the extraction of arthropods from various substrates such as nest material. However, little is known about its effectivity in extracting ectoparasites from penguin nests. This study aimed to assess the efficacy of a modified Berlese funnel method in extracting ectoparasites from African Penguin Spheniscus demersus nests and to determine differences in extraction capacity across parasite taxa and life stages. African Penguin nests (n = 278) were sampled at five penguin colonies along the south-west coast of South Africa in 2017. Nest samples were subjected to a modified Berlese funnel method with naphthalene as a repellent. Thereafter, all remaining ectoparasites were removed by hand sorting. Ectoparasite abundance was positively correlated between the two extraction methods (Spearman’s r = 0.73–0.89). Compared to total counts, flea (combined life stages and larvae) and total ectoparasite abundance and prevalence were significantly lower with the modified Berlese funnel method. In addition, adult flea and tick prevalence (but not abundance) was significantly lower with the modified Berlese funnel method compared with total counts. The modified Berlese funnel method fails as a quantitative method and can only provide a crude indication of the incidence of ectoparasites in penguin nests.     

Effect of ectoparasites on quality of pickled skins and their impact on the tanning industries in Amhara regional state,Ethiopia

Five groups of 20 infested skins with different ectoparasites and different levels of infestation and two groups of negative control skins from sheep and goats were examined for their corresponding defects at the pickled or wet blue stage of processing in tanneries. In addition, an analysis of skin defects was made from randomly selected processed skins at Kombolcha and Dessei tanneries. The prevalence of ‘ekek’ (cockle) at the pickled stage in Damalina ovis and Melophagus ovinus-infested sheep skins were 100 and 95%, respectively. Pickled goat skins affected by sarcoptic mange and Linognathus spp. were 100 and 0% positive for ‘ekek’ (cockle) lesion, respectively. The prevalence in control sheep and goat skins were 15 and 0%, respectively. There was a strong association (p < 0.05) between ‘ekek’ and infestation with M. ovinus and D. ovis in sheep and sarcoptic mange in goats. Follow-up of randomly selected 1000 pickled sheep skins and 1000 wet blue goat skins revealed that 71% of pickled sheep and 42% of wet blue goat skins had ‘ekek’ lesions. As the proportion of ‘ekek’ increased, the quality of graded skins decreased both in sheep and goats. Both on pickled sheep and wet blue goat skins, scratch and scars were found to have a strong association (p < 0.05) with ‘ekek’. The annual economic loses in 2002/2003 due to ‘ekek’ at the two tanneries was estimated to be 1.6 million USD for pickled sheep and 0.6 million USD for wet blue goat skins.     

Ectoparasitism and the role of green nesting material in the European starling

Summary The use of green nesting material is widespred among birds. Recent evidence suggests that birds use secondary chemicals contained in green plants to control ectoparasites. We manipulated green nesting material and ectoparasites of European starlings (Sturnus vulgaris) to test two hypotheses: (1) ectoparasites adversely affect prefledging survival and morphometrics or postfledging survival, and (2) green nesting material ameliorates the effects of ectoparasites. We recorded fat score, numbers of scabs, tarsal length, body mass, and hematocrit level on each nestling 17 days after hatching. We also fitted each nestling with unique patagial tags and resighted the starlings for 6–8 weeks after fledging to estimate survival and sighting rates. Nests devoid of green nesting material and dusted with the insecticide, carbaryl, had fewer high ectoparasite infestations, and nestlings had significantly lower scab scores, and significantly higher body masses than nestlings in undusted boxes. However, there was no difference in postfledging survival between birds from carbaryl-treated and undusted nests. There also was no difference in prefledging survival and morphometrics or postfledging survival between nestlings from boxes with and without green nesting material. These results do not support the hypothesis that starlings use green nesting material to control nest ectoparasites. We suggest an alternative hypothesis; green nesting material is used for mate selection or pairbonding in the starling.     

中国云南洱海周边褐家鼠的体表寄生虫群落组成

褐家鼠Rattus norvegicus可能是云南省部分鼠疫流行区的储存宿主之一, 其体表的某些寄生虫种类可能是人类疾病的传播媒介。为了解洱海周边地带褐家鼠的体表寄生虫群落, 并对其医学和兽医学的重要性进行描述。用U检验和相关分析的统计方法对2003-2004年采自云南洱海（中国滇西北著名的淡水湖泊）周边地区的431头褐家鼠的体表寄生虫群落进行了研究。用构成比（C）, 侵染率(P)和平均丰富度(A)反映体表寄生虫的流行和密度状况。调查点位于我国11大鼠疫自然疫源地之一, 此地也是我国恙虫病和流行性出血热的流行地区。结果表明: 431头褐家鼠中307头寄生有体表寄生虫, 侵染率为71%。采集到的体表寄生虫有47种, 包括23种恙螨、16种革螨、6种蚤和2种吸虱, 其中16种以前已经被证明是人类疾病的媒介。结果提示褐家鼠的体表寄生虫物种多样性高。     

Burrow Use and the Influence of Ectoparasites in Brants' Whistling Rat Parotomys brantsii

In Brants' whistling rat, Parotomys brantsii, single animals inhabit unusually complex burrow systems containing several nest chambers. We investigated burrow use and examined the effect of ectoparasites on choice of alternative nest chambers by radiotelemetrically monitoring the nocturnal sleeping locations of individual whistling rats, before and after treating them to remove ectoparasites. Prior to treatment, animals used several different nest chambers within a single burrow, moving from one chamber to another every 1.6 d on average, and most individuals also slept in more than one burrow. Anti‐parasite treatment reduced the rate at which animals switched from one nest chamber to another within a burrow. Screening of a separate sample of animals for ectoparasites revealed that they were infested with fleas, mainly Xenopsylla eridos. We suggest that by switching periodically from one nest chamber to another, whistling rats reduce the rate at which ectoparasites, especially fleas, accumulate.     

Isolation of collagen from the skins of Ehlers-Danlos syndrome-affected dogs by acetic acid extraction and pepsin digestion

Collagen was isolated by acetic acid extraction in the presence of protease inhibitors and also by pepsin digestion from the skins of dogs affected with the Ehlers-Danlos syndrome and the skins on non-affected dogs. The collagen preparations isolated by acetic acid extraction from the Ehlers-Danlos syndrome-affected dog skin contained a greater proportion of alpha-chains than the collagen preparations from the normal dog skin. When the collagen from the Ehlers-Danlos syndrome-affected dog skin was reduced with NaBH4 before heat denaturation, and electrophoresis, there was a greater proportion of beta-chains present. The collagen isolated from the normal dog skin was not affected by the NaBH4 reduction. Collagen preparations isolated by pepsin digestion from both the Ehlers-Danlos syndrome-affected dog skin and the non-affected dog skin contained the same quantity of alpha- and beta-chains. In addition, collagen from both affected and non-affected dog skins isolated by pepsin digestion contained 10-11% type III collagen as determined by the interrupted sodium dodecyl sulfate polyacrylamide gel electrophoresis method. Pepsin digestion of the collagens isolated by acetic acid extraction in the presence of protease inhibitors from the skins of affected and non-affected dogs eliminated the differences between the alpha:beta ratios of the affected and non-affected collagen preparations.     

Detection of Leishmania infantum in animals and their ectoparasites by conventional PCR and real time PCR

Visceral leishmaniosis (VL) is a parasitic disease caused by Leishmania infantum, which is primarily transmitted by phlebotomine sandflies. However, there has been much speculation on the role of other arthropods in the transmission of VL. Thus, the aim of this study was to assess the presence of L. infantum in cats, dogs and their ectoparasites in a VL-endemic area in northeastern Brazil. DNA was extracted from blood samples and ectoparasites, tested by conventional PCR (cPCR) and quantitative real time PCR (qPCR) targeting the L. infantum kinetoplast DNA. A total of 280 blood samples (from five cats and 275 dogs) and 117 ectoparasites from dogs were collected. Animals were apparently healthy and not previously tested by serological or molecular diagnostic methods. Overall, 213 (76.1 %) animals and 51 (43.6 %) ectoparasites were positive to L. infantum, with mean parasite loads of 795.2, 31.9 and 9.1 fg in dogs, cats and ectoparasites, respectively. Concerning the positivity between dogs and their ectoparasites, 32 (15.3 %) positive dogs were parasitized by positive ectoparasites. The overall concordance between the PCR protocols used was 59.2 %, with qPCR being more efficient than cPCR; 34.1 % of all positive samples were exclusively positive by qPCR. The high number of positive animals and ectoparasites also indicates that they could serve as sentinels or indicators of the circulation of L. infantum in risk areas.     

Biophysical Examinations of the Bending Stability of Various Stele Types and the Upright Axes of Early “Vascular” Land Plants

Biophysical methods allow quantitative deductions as to the “bending effectivity” of various stele types and the contribution of different tissues to the stability of upright plant axes. Considering the first occurrence of the different stele types in geological history, a strong tendency towards a higher “bending effectivity” can be observed. It can be shown that Rhynia gwynne-vaughanii, Aglaophyton major (Rhynia major) and Asteroxylon mackiei as well as probably the vast majority of early “vascular” land plants were turgor systems, i.e. that the parenchyma (when fully turgescent) is by far the most important contributory factor towards the bending stability of the upright axes.     

Evaluation of a cup scrub technique for quantification of the microbial flora on bovine skin

L loyd , D.H. 1984. Evaluation of a cup scrub technique for quantification of the microbial flora on bovine skin. Journal of Applied Bacteriology 56 , 103–107.
A cup-scrub technique devised for sampling the human skin surface microfiora was evaluated in cattle. Scrub samples from bovine skin contained clumps of squames and bacterial microcolonies which were progressively broken down by shaking. This was accelerated in the presence of ballotini beads but aggregations of bacteria were still present after prolonged agitation. Vigorous shaking, particularly with beads, decreased the viability of the bacteria and optimum viable counts were obtained after manual shaking for half a minute. Immersion in buffered detergent, wash and diluting fluids for up to 2 h promoted release of bacteria from micro-colonies but decreased the viability of aerobic and anaerobic pleomorphic rods and a Bacillus strain. There was no significant effect on strains of Micrococcaceae. Prolonged exposure of bacteria from scrub samples to these fluids can thus lead to both quantitative and qualitative alterations in the counts: obtained, although these effects may be masked by the continuing release of bacteria from microcolonies. The cup-scrub technique provides a convenient means of quantifying changes in the bovine skin microfiora but results obtained from different studies should only be compared if closely similar techniques are used.     

Restoration of Florida scrub vegetation in an old field through 23 years after planting

Florida scrub, a fire‐maintained, xeromorphic shrubland, hosts many rare and declining species, but most scrub habitat has been lost to development and agriculture. Formerly cultivated sites offer an opportunity to restore Florida scrub. In this 23‐year study, we test whether scrub species could be restored to an old field and whether scrub vegetation composition and structure could be reestablished over time. Scrub oaks were planted in a section of an old field in 1992 after the site was cleared and treated with herbicide. Additional oaks and other scrub species were planted in 1993. We determined survival and growth annually of a marked sample of scrub species. We sampled vegetation cover in two height strata annually on 10 permanent line‐intercept transects in the old grove and on 20 transects in adjacent, intact scrub. Initial survival of Quercus geminata exceeded that of Q. chapmanii or Q. myrtifolia. Cover of scrub oaks greater than 0.5 m increased from 1.3% in 1992 to 65.2% in 2010. However, the vegetation structure of large Q. geminata did not resemble that of native scrub. Adaptive management led to cutting large oaks in the fall of 2010, and burning the site in early 2011. Cutting and burning appeared to stimulate sprouting and clonal spread of scrub oaks. Ordination analysis indicated directional change related to increasing scrub oak cover and time since planting but the old field still differed from intact scrub. Vegetation has developed toward scrub composition and structure but exotic grasses persist.     

Microhabitat preference constrains invasive spread of non-native natal grass (<Emphasis Type="Italic">Melinis repens</Emphasis>)

Preventing the establishment of a non-native species is critical for ensuring the species does not become invasive, yet most non-native species will have little impact on their environment. Despite this, little is known about what influences whether a species will remain relatively benign, or whether it will cause economic or ecological harm. Understanding a plant’s microhabitat provides insight into the necessary conditions for establishment and the current distribution limitations of a population. We investigated microhabitat preference of the non-native natal grass (Melinis repens (Willd.) Zizka) in Florida scrub using microhabitat sampling to measure vegetation composition. We examined the extent to which microhabitats were associated with natal grass presence and biomass in invaded disturbed scrub and roadside plots using backwards stepwise logistic regression and general linear models to identify significant microhabitat variables. We further compared these plots with those in undisturbed, uninvaded scrub to characterize vegetation across habitat types, and used our model to predict the probability of natal grass invasion in undisturbed scrub. Natal grass preferred microhabitats with high litter volume and distance to shrubs and intermediate cactus, graminoid, and vine cover. Roadside natal grass achieved higher biomass and was less microhabitat limited than disturbed scrub natal grass. We determined that undisturbed scrub plots represent distinct microhabitats that natal grass is unlikely to invade. Microhabitat sampling provides land-managers a non-intrusive technique to assess potential habitat suitability based non-native plant preferences before a costly invasion occurs.     

Isolation and Characterization of Cuticular Polyester from the Leaf of Nicotiana tabacum

Cuticular membranes (ca.0.04mg/cm²) were isolated from fresh and flue-cured tobacco leaves (Nicotiana tabacum) as clear, colorless and thin films by oxalic ammonium treatment and successive cellulase-pectinase digestion. GC-MS analyses, after hydrogenolysis and trimethylsilylation, revealed that the membranes are mainly built up of 10,16-dihydroxy hexadecanoic acid in a polyester network structure which survives postharvest-treatments.

The fruit skins of solanaceaes; sweet pepper (Capsicum annuum), eggplant (Solanum melongena) and tomato (Solanum lycopersicum), have similar membranes which are essentially composed of 9,16- and 10,16-dihydroxy hexadecanoic acid.     

Structure of a unique inland mangrove forest assemblage in fossil lagoons on the Caribbean Coast of Mexico

Scrub mangrove wetlands colonize the intertidal zone of fossil lagoons located in carbonate continental margins along the Yucatan Peninsula of Mexico. These unique ecological types were investigated in October, 1994, by locating transects in several mangrove forests along the Caribbean coast of the peninsula. Four species of mangrove occurred at these sites including Rhizophora mangle, Avicennia germinans, Laguncularia racemosa, Conocarpus erecta. This is one of the first examples of a species rich scrub forest. The mangroves fell into three height categories: short scrub less than 1.5 m, tall scrub to 3.0 m, and basin forests between 4.5 and 6 m. Average height, diameter (dbh), basal area, and complexity index generally increased from short scrub to basin forests. Basal area, ranged from 0.16 m² ha^–1 in a short scrub forest intermixed with Cladium jamaicense to 12.9 m² ha^–1 in a basin forest. Density ranged from 1520 trees ha^–1 to over 25,000 trees ha^–1 in a short scrub forest dominated by R. mangle. The complexity index ranged from 0.01 to 8.3. Height, dbh, basal area, and complexity index were positively related. A number of trees were growing as sprouts from larger downed trunks, suggesting that hurricanes, such as Gilbert that occurred in 1988, are important in controlling the structure of these forests. These forests appear isolated from the sea, but are influenced by groundwater exchange occurring at the land-margin zone.     

Polymorphic microsatellite markers for the Florida scrub lizard (Sceloporus woodi)

The Florida scrub lizard (Sceloporus woodi) is one of a suite of species restricted to Florida scrub, a threatened ecosystem. We characterized eight microsatellite loci from scrub lizards based on screening of 75–91 individuals per locus. Polymorphism was high (8–20 alleles per locus). Observed and expected heterozygosities ranged from 0.32–0.83 and 0.77–0.91, respectively. These markers will be useful for population‐level analyses and can contribute to a genetic foundation for conservation strategies for this endemic species.     

生物活组织的背向二次谐波成像

光学二次谐波成像技术由于具有三维高分辨率、不需要荧光标记、对生物样品的杀伤效应小等特点,在生物医学研究上具有广阔的应用前景.在双光子荧光成像基础上,实现了适合对厚组织样品观测的背向光学二次谐波成像,探讨了背向二次谐波成像的特点和影响因素.通过对多种生物组织样品进行大量实验,发现胶原纤维和肌肉纤维均可以产生很强的背向二次谐波,并成功地将背向二次谐波成像技术应用于糖尿病患者皮肤的观测.背向二次谐波成像技术可望推广到病理检查等临床应用中.     

High resilience to extreme climatic changes in the CAM epiphyte Tillandsia utriculata L. (Bromeliaceae)

Climate change is expected to increase the frequency of extreme climatic events, yet few studies have addressed the capacity of plant species to deal with such events. Species that are widespread are predicted to be highly plastic and able to acclimate to highly changing conditions. To study the plasticity in physiological responses of the widely distributed epiphyte Tillandsia utriculata, we transplanted individuals from a coastal scrub and broadleaf evergreen forest to a similar coastal scrub site and forest. After a 45-day acclimation, the plants were moved to a semi-controlled greenhouse at each site, and then subjected to a 20-day drought. Physiological variables were measured during the acclimation and the drought. The individuals of scrub and forest populations had similar relative water content and carbon assimilation in the contrasting conditions of the two transplantation sites despite the high discrepancy between the environments at their original site. Electron transport rates were higher in individuals from the scrub population. Electron transport rates were also higher than estimated from carbon assimilation, suggesting that photorespiration was present. The individuals of the coastal scrub population had a higher capacity to dissipate excess energy this way. The relative distance index of plasticity was high overall, indicating that some traits are highly plastic (titratable acidity, carbon assimilation) in order to maintain the stability of others (maximum quantum yield F_v/F_m and relative water content). We conclude that T. utriculata is a highly plastic species with a high capacity to tolerate extreme environmental changes over a short time.     

The efficiency of patch sampling for determination of relative tick burdens in comparison with total tick counts

Quanttative data on host tick burdens ar fundamental for the initiation of control strategies and effective management of wildlife populations, but the methods of live sampling employed for domestic animals are unsuitable for sampling wild animals. Despite advances in the use of destructive methods (the scrub and digestion techniques) to obtain measures of the total tick burden on wildlife, these methods are too involved for many field workers, who often need only measures of relative tick burden. Recently, patch sampling methods have been introduced whereby only certain predilection sites are sampled, the presumption being that the number of ticks collected gives an indiccation of the relative degree of infestation. We examined the validity of patch sampling as a measure of relative tick burden by comparing adult ticks collected from the ears, head, neck, foreleg and perianal region of impala (aepyceros melampus) with total tick burdens of the same animals derived from the digestion technique. Adult ticks from patch sampling were positively and significantly correlated with total adults and total ticks (larvae, nymphs, and adults) on impala, with ticks patch sampled from the neck showing the highest correlation with the total tick burden. Comparison of relative tick loads from patch sampling with absolute tick loads from digestion for three classes of impala (females, bachelor males and territorial males) gave qualitatively similar results. We conclude that, when measures of relative tick load are sufficient and destructive sampling is not feasible, patch sampling can provide reliable information on relative tick burdens that are positively correlated with the total tick burden.     

Abundances and host relationships of chigger mites in Yunnan Province,China

This paper reports on ectoparasitic chigger mites found on small mammals in Yunnan Province, southwest China. Data were accumulated from 19 investigation sites (counties) between 2001 and 2009. A total of 10 222 small mammal hosts were captured and identified; these represented 62 species, 34 genera and 11 families in five orders. From the body surfaces of these 10 222 hosts, a total of 92 990 chigger mites were collected and identified microscopically. These represented 224 species, 22 genera and three subfamilies in the family Trombiculidae (Trombidiformes). Small mammals were commonly found to be infested by chigger mites and most host species harboured several species of mite. The species diversity of chigger mites in Yunnan was much higher than diversities reported previously in other provinces of China and in other countries. A single species of rodent, Eothenomys miletus (Rodentia: Cricetidae), carried 111 species of chigger mite, thus demonstrating the highest species diversity and heaviest mite infestation of all recorded hosts. This diversity is exceptional compared with that of other ectoparasites. Of the total 224 mite species, 21 species accounted for 82.2% of all mites counted. Two species acting as major vectors for scrub typhus (tsutsugamushi disease), Leptotrombidium scutellare and Leptotrombidium deliense, were identified as the dominant mite species in this sample. In addition to these two major vectors, 12 potential or suspected vector species were found. Most species of chigger mite had a wide range of hosts and low host specificity. For example, L. scutellare parasitized 30 species of host. The low host specificity of chigger mites may increase their probability of encountering humans, as well as their transmission of scrub typhus among different hosts. Hierarchical clustering analysis showed that similarities between different chigger mite communities on the 18 main species of small mammal host did not accord with the taxonomic affinity of the hosts. This suggests that the distribution of chigger mites may be strongly influenced by the environment in which hosts live.     

In vitro andin vivo nitrogenase activity ofRhizobium mutants and their symbiotic effectivity

A slow growing nitrogen-fixing strain ofVigna radiata var.aureus (mung bean)Rhizobium which expressed nitrogenase activity in a synthetic medium was isolated from its native population. Mutants with decreased and increased nitrogenase activity were derived from this strain by treatment with acridine orange and ethidium bromide. These mutants were tested for symbiotic effectivity invivo. The effectivity of mutants with decreased nitrogenase activity in the culture medium was lower than the parent strain; however, the effectivity of mutants with higher nitrogenase activity did not increase above that of the parent. This suggests that the plant is perhaps a limiting factor in the full expression of rhizobial nitrogenase in the nodules.